Control method of air intake and air exhaust valves of internal combustion engine

Abstract

The invention provides a control method of air intake and air exhaust valves of an internal combustion engine, which belongs to the field of air intake and air exhaust systems of internal combustion engines. The control method of the air intake and air exhaust valves is based on thermodynamic cycle of high pneumatic compression ratio and low expansion ratio so as to ensure that the air exhaust valve is opened as soon as possible and the opening/closing time of the air intake valve is properly adjusted when a turbocharged internal combustion engine is under a low-speed and large-torque working condition, a highland operation working condition and an acceleration working condition, therefore, air intake flow is ensured to be increased as much as possible under the working conditions. Meanwhile, a passage is arranged between an air intake pipe behind a compressor and an air exhaust pipe before a turbocharger; air of low temperature is introduced into the air exhaust pipe to reduce exhaust temperature so as to protect the turbocharger; when cold start is carried out, the air exhaust valve is opened later to enhance compression temperature in a cylinder; and once the start is carried out, the air exhaust valve is opened early to increase the air intake quantity. The control method can largely enhance the dynamic property of the internal combustion engine under the low-speed and large-torque working condition and the highland working condition, improve the start performance and acceleration performance of the internal combustion engine and enable the internal combustion engine to obtain a better emission performance.

Description

technical field [0001] The invention relates to a method for controlling an intake and exhaust valve of an internal combustion engine, belonging to the field of intake and exhaust systems of an internal combustion engine. Background technique [0002] With the rapid increase of the number of automobiles, the continuous rise of world oil prices, and the increasingly serious air pollution, the problem of how to effectively improve the energy utilization rate of internal combustion engines and reduce emissions has become increasingly urgent. Currently there are mainly the following problems: [0003] 1) Since the new technology of turbocharging can improve the combustion rate of the internal combustion engine and reduce the emission of harmful gases, it has become a major trend in the development of internal combustion engines to equip turbochargers. However, under high speed and heavy load, the vortex The thermal and mechanical loads of the blades are too high, the torque of...

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Problems solved by technology

[0006] The purpose of the present invention is to solve the problem in the field of internal combustion engine research above-mentioned by selecting an appropriate variable valve system and designing a

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